Add a "check" target to make regress work nicely.

--- Makefile.orig	Sat Jul 26 00:44:43 2003
+++ Makefile	Sun Aug  3 15:46:52 2003
@@ -420,3 +420,17 @@
 
 # -----------------------------------------------------------------------------
 
+check::
+	( cd testsuite/tests/ghc-regress ; $(MAKE) $(MFLAGS) )
+	@(sed 's/ started at .*$$//' actual.result > actual.result_)
+	@(if cmp -s `uname -m`.expected.result actual.result_ ; then \
+                echo "All is good!" ; \
+          else \
+                echo ;\
+                echo "@@@@@@@@@@@@@@@@@@@@@@@@@@@@";\
+                echo "Unexpected regress results!" ;\
+                echo "@@@@@@@@@@@@@@@@@@@@@@@@@@@@";\
+                echo ;\
+                echo "here is a diff:" ;\
+                diff -u `uname -m`.expected.result actual.result_ ;\
+          fi ; exit 0 )
